In industry gas compression devices, particularly compressed nitrogen gas devices, are used frequently for repetitive tasks, such as recall movements of slide blocks, or extraction of pieces stamped into, or lodged in industrial pressing tools.
The intensive use in an industrial environment of commercial mass-production methods necessitates a very considerable number of cycles of usage of such compression devices, frequently exceeding one million cycles. Furthermore the working conditions thereof are sometimes extreme, and it is therefore necessary that these devices be built robustly for long-term reliability.
This required robust long-term reliability must even exceed the conditions generally prevailing in these domains of industrial utilization.
The primary source of defects generally occurs in the area of sealing, the maintenance of which cannot be guaranteed completely for long time periods during intensive and extended utilization of the compressive device.
In fact, because of the sequential occurance of the work cycles, the partially soft sealing joint, with which the majority of compressive devices of the prior art are equipped, deteriorates and weakens quickly, and thus not only no longer provides a sufficiently adequate sealing integrity, but also ceases to provide a steady abutment for the piston in its extended position.
Even more recent compressive devices, which have joints of greater resistance, are vulnerable to damage by extrusion, which in turn leads quickly to a sealing defect.
Compressive devices of the aforedescribed kind then are no longer suitable, in that state, for being used for the intended application.
Furthermore the assembled body of the compressive device, called upon to perform intensive repetitive work, heats up excessively, which causes a pronounced decline in performance, and a more-or-less rapid deterioration of the assembly.
Additionally, on one hand, after a considerable number of working cycles, there occurs a diffusion of the nitrogen gas into the lubrication chamber, and, on the other hand, there take place multiple leakages of the lubrication liquid, which show up on the exterior of the compression device.
The gas compression device of the prior art thus no longer produces the force required of it, and furthermore malfunctions occasionally at the very time the desired element is produced, and in certain cases, because the faults are amplified, causes even a deterioration of the pressing tool.